Processed meats such as bacon and hot dogs are linked to mental breakdowns, a study suggests.
Patients taken to hospital with manic episodes were more than three times more likely to have recently eaten meats such as ham, salami or beef jerky.
Scientists believe this could be because the foods contain the chemical nitrate, which is used to preserve them.
Rats fed a diet with added nitrates showed mania-like hyperactivity after just a few weeks in separate tests. Co-author Seva Khambadkone, from Johns Hopkins University School of Medicine in Baltimore, US, said: “Nitrated cured meat could be one environmental player in mediating mania."
The study followed 1,101 people aged 18 to 65 with and without psychiatric disorders between 2007 and 2017. Researchers initially suspected viruses in food could trigger episodes. Co-author Prof Robert Yolken said: “We looked at a number of different dietary exposures and cured meat really stood out.”
A previous study has shown that bipolar patients given a probiotics – or good bacteria – are less likely to be hospitalised for a manic episode in the following six months.
The new findings do not claim the meats directly cause manic episodes but say they could contribute to them.